Category: Wild relatives

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“It was serendipity that we had the seeds lying around”

Our title is evolutionary geneticist Arthur Weis to journalist Carl Zimmer on the topic of an experiment he and colleagues at UC Irvine carried out a few years ago where they compared those seeds — that had been “lying around” in the intervening few years in a cool, dry place — with seeds of the same species newly collected from the same sites. The result of the experiment was that…

…[t]he newer plants grew to smaller sizes, produced fewer flowers, and, most dramatically, produced those flowers eight days earlier in the spring. The changing climate had, in other words, driven the field mustard plants to evolve over just a few years.

The point of Zimmer’s article is that evolution can take place over short periods of time, and that because of climate change “life will undergo an evolutionary explosion.” ((We’ve blogged about this before.)) What Zimmer doesn’t say is that we have about 6.5 million similar samples of seeds in the world’s crop genebanks, and not by serendipity. Some date back decades. There would be a great research programme in comparing the genetic makeup of those samples with newer samples. Assuming that the populations are still there. And that there is enough documentation associated with the samples to find their original collecting sites.

A final thought. The assumptions behind the ecological niche modeling work which has been proliferating of late to predict changes in distributions, for example of crop wild relatives, is that the species don’t move or evolve fast enough to keep pace with climate change. They may well in fact evolve, adapt and survive, and that would certainly be a good thing. But helping them do that through in situ protection should not be an argument for downplaying the complementary importance of ex situ conservation. After all, with the kind of selection pressures likely to be involved, populations are very likely to be significantly genetically narrower in the future. Whether the species adapts or not, we’ll still need to collect seeds and store them in genebanks if we are to have available for use as much as possible of the genetic diversity that is currently — just — still in the field.

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Nibbles: Dogs squared, Afghanistan’s poppies, Rice at IRRI, Book on sapodilla chicle in Mexico, Opuntia, Trees

  • DNA survey of African village dogs reveals as much diversity as in East Asian village dogs, undermines current ideas about where domestication took place.
  • Fossil doubles age of dog domestication.
  • “When children felt like buying candy, they ran into their father’s fields and returned with a few grams of opium folded inside a leaf.”
  • “The rice, a traditional variety called kintoman, came from my grandfather’s farm. It had an inviting aroma, tasty, puffy and sweet. Unfortunately, it is rarely planted today.”
  • “An era of synthetic gums ushered in the near death of their profession, and there are only a handful of men that still make a living by passing their days in the jungle collecting chicle latex…The generational changes in this boom-and-bust lifestyle reflect a pattern that has occurred with numerous extractive economies…”
  • Morocco markets prickly pear cactus products.
  • TreeAid says that sustainable agriculture depends on, well, trees.
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Multiple origins of agriculture debated

The point is that agriculture, like modern human behaviour, was not a one time great invention, but the product of social and environmental circumstances to which human groups with the same cognitive potential responded in parallel ways. The question in both cases is: what were the common denominators of those circumstances?

That’s from a post over at The Archaeobotanist which starts by talking about “modern human behaviour” rather than agriculture, but sees parallel processes at play in the origin of both. So, in the same way that “the cognitive architecture for modern behaviour was around but the innovations that we regard as ‘modern’ emerged when social and environmental circumstances demanded,” and this happened in different places at different times, so likewise the “cognitive architecture” for agriculture was widespread and there were therefore many “centres in which societies converged on agriculture,” with the concomitant “behavioural changes towards manipulation of the environment in favour of the reproduction of a few food species,” triggered by particular “social and environmental circumstances.”

Fair enough, but how is this new? There’s a comment on the post in which Paul Gepts makes this very point

…I am somewhat surprised that the issue of parallel inventions of agriculture is still an issue. The concept of centers of origin/domestication has been around for a century, thanks to Vavilov, Harlan, et al. … I must be missing something here, because for some time agriculture has been considered an example of multiple, independent inventions.

I’m looking forward to following this heavyweight exchange.